For example, Japanese Patent Application Publication No. 2008-238792 discloses a system in which liquid is supplied from a cartridge to a tank due to hydraulic head pressure, and then supplied from the tank to a head (consuming portion) configured to consume liquid. In the system disclosed in Japanese Patent Application Publication No. 2008-238792, a sensor configured to detect displacement of a sensor arm provided in the cartridge is used to determine a remaining amount of the liquid in the cartridge.
In the meantime, in another system in which liquid is supplied to a tank due to hydraulic head pressure, in order to detect a remaining amount of liquid in the cartridge, a remaining amount of the liquid in the corresponding tank is detected using a sensor rather than directly detecting the remaining amount of the liquid in the cartridge by providing a sensor arm in the cartridge.